.\" RCSid "$Id: ran2tiff.1,v 1.3 2008/11/10 19:08:17 greg Exp $"
.TH RAN2TIFF 1 9/16/2005 RADIANCE
.SH NAME
ran2tiff - expose and convert a RADIANCE animation to TIFF frames
.SH SYNOPSIS
.B ran2tiff
[
.B "-W prev_frame_wt"
][
.B "-H histo"
][
.B "-D dir"
]
[
.B "pcond opts"
]
[
.B "ra_tiff opts"
]
.B "frame1.hdr frame2.hdr .."
.SH DESCRIPTION
.I Ran2tiff
takes an animated sequence of Radiance pictures and converts them by calling
.I pcond(1)
and
.I ra_tiff(1)
in such a way that exposure changes gradually
from one frame to the next.
It accomplishes this by computing a histogram for each image and
blending it with a weighted histogram from the previous frame,
where the weight is set by the
.I \-W
option, or 0.9 by default.
A value of 0.5 would mean that the previous frame carries 1/2 the weight
of the current one, and the frame before that 1/4, 1/8 before that,
and so on.
.PP
The
.I \-H
option specifies a histogram file to be used to ensure continuous
exposure between the current sequence and one before it.
If the file does not exist, it will be created at the end of
the conversion.
If it does exist, its contents will be used as the histogram
at the end of the previous sequence.
.PP
The
.I \-D
option may be used to specify an output directory for the resulting
TIFF frames.
Otherwise, the current directory will be used.
The output file names will correspond to the input names, but
with a ".tif" suffix.
.PP
Ran2tiff also accepts the standard options for
.I pcond
and
.I ra_tiff,
though output to LogLuv TIFF formats is not supported.
(There would be no point in adjusting the exposure if the output were HDR.)\0
.SH EXAMPLE
To convert a sequence of frames using a rapid human exposure response
and LZW compression on the output:
.IP "" .2i
ran2tiff \-W 0.7 \-h \-z frame*.hdr
.PP
Similar to
.I fieldcomb(1),
this program works well with the "TRANSFER" facility of
.I ranimate(1).
.SH AUTHOR
Greg Ward
.SH "SEE ALSO"
fieldcomb(1), getinfo(1), pcond(1), pfilt(1), phisto(1),
ra_tiff(1), ranimate(1), rpict(1)
